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Boot Assist Module (BAM)
MPC5566 Microcontroller Reference Manual, Rev. 2
16-16
Freescale Semiconductor
it receives the echo from the previous message. A FlexCAN message sent before the echo is
received is ignored.
NOTE
Internal SRAM is protected by 64-bit error correction (ECC) hardware. All
writes to uninitialized internal SRAM must be 64-bits wide, or an ECC error
occurs. The BAM buffers 8 bytes of downloaded data before executing a
single 64-bit write. Only internal SRAM supports 64-bit writes.
Downloading data to other RAM causes errors.
If the start address of the downloaded data is not at an 8-byte boundary, the
BAM writes 0x00 to the memory locations from the preceding 8-byte
boundary to the start address (maximum 4 bytes). The BAM also writes
0x00 to all memory locations from the last byte of data downloaded to the
following 8-byte boundary (maximum 7 bytes).
4. Execute code.
The BAM waits for the last FlexCAN message transmission to complete. Then the FlexCAN
controller is disabled. CNTXA and CNRXA become GPIO inputs. The BAM branches to the
starting address of the downloaded code, as specified in step 2.
NOTE
The code that downloads and executes must:
•
Periodically refresh the e200z6 watchdog timer; or
•
Change the timeout period to a value that does not cause resets during normal operation.
Table 16-11. FlexCAN Serial Boot Mode Download Process
Step
Host Message Sent
MCU Response
Message
Action
1
FlexCAN ID =
0x011 + 64-bit password
FlexCAN ID =
0x001 + 64-bit password
Password checked for validity and compared
against stored password. e200z6 watchdog timer is
refreshed if the password check is successful.
2
FlexCAN ID =
0x012 + 32-bit store address
+ 32-bit number of bytes
FlexCAN ID =
0x002 + 32-bit store address
+ 32-bit number of bytes
The load address and the number of bytes to
download are stored for future use.
3
FlexCAN ID =
0x013 + 8 to 64 bits of raw
binary data
FlexCAN ID =
0x003 + 8 to 64 bits of raw
binary data
Each data byte received is written to MCU memory,
starting at the address specified in the previous
step and incrementing until the number of data
bytes received and stored matches the number of
bytes to download and store (specified in step 2).
4
None
None
The BAM program returns I/O pins and the
FlexCAN module to their reset state, then branches
to the start address of the stored data (specified in
step 2).
Summary of Contents for MPC5566
Page 81: ...Introduction MPC5566 Microcontroller Reference Manual Rev 2 1 24 Freescale Semiconductor...
Page 135: ...Signal Description MPC5566 Microcontroller Reference Manual Rev 2 2 54 Freescale Semiconductor...
Page 189: ...Reset MPC5566 Microcontroller Reference Manual Rev 2 4 20 Freescale Semiconductor...
Page 603: ...Flash Memory MPC5566 Microcontroller Reference Manual Rev 2 13 38 Freescale Semiconductor...
Page 609: ...SRAM MPC5566 Microcontroller Reference Manual Rev 2 14 6 Freescale Semiconductor...
Page 1073: ...MPC5566 Microcontroller Reference Manual Rev 2 22 36 Freescale Semiconductor...
Page 1185: ...Nexus MPC5566 Microcontroller Reference Manual Rev 2 25 92 Freescale Semiconductor...